Enterasys Networks Security Router X-PeditionTM - Manual (Page 47)

Utilizing the Command Line Interface
XSR User’s Guide 2-11
The first phase establishes a physical connection (training) on the ADLS line. RAI ADSL attempts a
physical connection on the first port of the ADSL card, waiting one minute for training to succeed.
If it fails, RAI abandons ADSL RAI and moves to the next available RAI method.
After training with the DSLAM, RAI must configure a proper PVC channel on the ADSL line. In
this discovery hase, PVCs on a particular ADSL line are preconfigured on the DSLAM that
terminates the ADSL physical line. In order to discover VPI and VCI numbers for the PVC, RAI
ADSL sends F5 OAM cells on the line and collects responses (if any) from the the DSLAM. RAI
searches PVCs starting from VPI = 0/VCI = 30 and stops on VPI=128/VCI=128. Because ADSL
RAI conducts a linear search of the VPI/VCI space, searching for a PVC with high VPI/VCI
values can be lengthy. Currently, RAI does not support preconfigured VPI/VCI numbers.
RAI stays in discovery phase until it finds the first PVC that responds on OAM cells or until it
exhausts the PVC space in which case it abandons ADSL RAI and moves to the next available RAI
method.
In the port setting phase, RAI configures sub-interface 1 on the first port of the ADSL card ( atm
0.1 ) with the discovered PVC. If there is more than one discovered PVC, RAI begins with the first
one. ADSL RAI tries two PPPoE encapsulations - SNAP and MUX. If authentication is required,
RAI ADSL uses CHAP or PAP and takes the serial number of the XSR as its username and
password - the PPPoE server must be configured with the XSR serial number to authenticate
successfully. If authentication succeeds, the IP address is retrieved from the PPPoE server and the
IP layer comes up. RAI ADSL waits one minute for authentication and the IP connection to come
up. If it times out, it proceeds to the next encapsulation, or if both encapsulation types fail, for that
PVC to try the next discovered PVC. In a case where there are no other PVCs to try, RAI abandons
ADSL RAI and moves on to the next RAI method.
The final phase involves TFTP, where RAI downloads the startup file. This phase is common to
other RAI methods. Because TFTP broadcasts the request for the TFTP server, it is important that
the server terminating the PPPoE session direct this request to the TFTP server (using the IP helper
address). The startup file name is the serial number of the device.
If TFTP fails and PVCs exist that were not previously tried for configuration, RAI returns to
PPPoE negotiation and reconfigures the ATM 0.1 interface with a new PVC. Otherwise, it
abandons ADSL RAI and moves on to the next RAI method.
CLI Editing Rules
To use the CLI efficiently, be aware of the following rules:
• Case-sensitivity: CLI commands are not case-sensitive. For example, you can enter either SHOW
VERSION or show version to display the XSR's software revision. But, some parameters may be
case sensitive. For example, entering snmp-server community public is different from
snmp-server community PUblic
• Command Abbreviation: You can abbreviate commands and keywords to the minimum number
of characters that define a unique abbreviation. For example, you can abbreviate the
hostname
command to hostn (but you cannot abbreviate to hos because other commands also start with
the letters hos ).
• Output Display: By default, output data are displayed one page at a time if the data occupies
more than one page. In this case, you can use the spacebar to scroll down to the next page or
press
ENTER to scroll down one line at a time. The default page size is 132 characters wide, 23
rows high and they are configurable in a range from 0 to 512 characters using the terminal
command. Refer to the XSR CLI Reference Guide for more information about the command.